(a) Field of the Invention
The present invention relates to a system and a method for generating line pressure for a continuously variable transmission (CVT) in a hybrid vehicle. More particularly, the present invention relates to a system and a method for generating line pressure for a CVT in a hybrid vehicle in which the line pressure of the CVT is maintained as constant even in an idle stop state of an engine.
(b) Description of the Related Art
A hybrid vehicle is a vehicle having both an engine for generating power by combusting a fuel and a motor for outputting power of a battery. A hybrid vehicle controls operation of the engine and the motor, and thus, a fuel consumption rate can be enhanced and a noise and an exhaust gas can be reduced.
In addition, a hybrid vehicle has a characteristic of performing power delivery when the engine is restarted in an idle stop state of the engine.
Two methods for generating the line pressure for the CVT in a hybrid vehicle are known. The first method generates the line pressure by receiving power from a power source of the engine when the engine is operated. The second method generates the line pressure by using an additional drive motor.
However, the line pressure of the CVT is generated after the engine is started according to such methods. Thus, exhaust performance and power performance may be deteriorated during a delay time for generating sufficient line pressure.
In addition, speed and torque differences between an input element and an output element may occur during the delay time for generating sufficient line pressure. Thus, an impact may occur when the engine is restarted in the idle stop state of the engine.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.